1. Field of the Invention
The present invention relates generally to methods for controlling an automobile climate control system and a control system useful therefor in which the automobile has a convertible top and, more particularly, the automobile has both an automatic climate control system and a manual climate control system.
2. Description of the Related Art
Today's automobiles are equipped with climate control systems which include manual climate control systems and may optionally include automatic climate control systems, both of which control the temperature in the passenger compartment, also referred to as the "interior temperature". The climate control systems control the use of devices, such as blower fans, air conditioning units, heating devices, and air-mix doors or other suitable variable-position air-blending mechanisms.
A manual climate control system includes a control panel through which a passenger may select a desired interior temperature, control the speed of the blower fan, control the air flow direction, and select use of the air conditioning unit or heating device.
An automatic climate control system controls the interior temperature of the automobile without input from the automobile's passengers except for the desired temperature. An automatic climate control system typically includes an ambient temperature sensor for sensing the ambient temperature outside of the automobile, an actual temperature sensor for sensing the actual interior temperature at a given location within the automobile's passenger compartment, a sun-load sensor which senses the relative amount of solar radiation reaching the interior of the automobile, a control panel through which a passenger may select a desired interior temperature, and a control unit which receives the various values from the sensors and the passenger's temperature selection and produces various signals to control the operation of any air conditioning devices, heating devices, blower fans, air flow direction devices, and air-mix doors.
An automobile equipped with an automatic climate control system and which happens to have a convertible top can meet with some operational problems when the convertible top is retracted (down) and the automatic climate control system is operating. For example, when the convertible top is retracted, the interior temperature reading is corrupted by the ambient (outside) temperature which will cause the control unit to attempt to compensate for an inaccurate temperature reading. When operating under these conditions, the climate control system will become unstable or the blower fan may be caused to "lock-up" in high speed.
It is, therefore, one object of the present invention to provide a method for controlling a climate control system of an automobile equipped with a convertible top, so that the climate control system operates more smoothly when the convertible top is retracted than it does without the method.
It is another object of the present invention to provide a special control system useful for controlling a climate control system of an automobile equipped with a convertible top, which special control system causes the climate control system to operate more smoothly when the convertible top is retracted than it does without the control system.